• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.2
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• pp.154-159
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• 2013

In this paper, the effect of bolt clamping force and form accuray of contact surface between mirror and mount on mirror surface was studied. Normally, mirror used in reflecting optical system was assembled with mount by bolts or adhesive. In this case, the tension caused by bolt clamping force or adhesive force may distort the mirror surface. Also, form accuracy error of the contact surface have a negative impact on wrenched mirror surface which assembled by bolts or adhesive. In this study, stress and distorted displacements on mirror surface were analyzed according to the different contact surface form accuracies and bolt clamping forces by using the finite element analysis method.

• KIPE Magazine
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• v.10 no.5
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• pp.29-32
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• 2005

• STIMA Bulletin
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• s.6
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• pp.35-47
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• 2007

• 기계와재료
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• v.15 no.3 s.57
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• pp.21-28
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• 2003

• The Bulletin of The Korean Astronomical Society
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• v.25 no.1
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• pp.23-23
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• 2000

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.679-691
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• 2020

In the future, 5G technology will become the core infrastructure driving the 4th industrial era. For intelligent super-convergence service, it will be necessary to collect various personal information such as location data. If a person's high-precision location information is exposed by a malicious person, it can be a serious privacy risk. In the past, various approaches have been researched through encryption and obfuscation to protect location information privacy. In this paper, we proposed a new technique that enables statistical query and data analysis without exposing location information. The proposed method does not allow the original to be re-identified through polynomial-based transform processing. In addition, since the quality of the original data is not compromised, the usability of positioning big data can be maximized.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.12
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• pp.993-998
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• 2017

In this paper, a high-accuracy current sensing technique for three-phase current paths in an electrical switchboard is proposed. Conventional open-style current sensors using magnetic sensors show inaccurate sensing performance with more than 10% error due to undesired magnetic field interference from neighboring paths. To increase accuracy, large and expensive current transformers with large permeabilities have been used, which increased the cost and size. The proposed technique can improve the measured magnetic field by the calculation of magnetic interference effect from neighboring current paths. The relationship between neighboring magnetic fields and the desired magnetic field is theoretically analyzed in a general case. The proposed technique is verified using magnetic field simulations in a three-phase busbar environment.

• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.64-69
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• 2018

Automatic test equipment for field maintenance of aircraft mounted equipment is effective for integrated design when operating a small number of aircraft for special purposes. The integrated automatic test equipment identifies commonly used interfaces and is used for branching or generating routes for each unit under test specific inspection. High-precision signals such as RTD, TC, and analog voltage can cause measurement errors due to conduction resistance during signal branching and connection when generating branches and paths. The measurement error caused by the resistance of the wire leads to a lot of restrictions in designing the equipment to be inspected. In this paper, we propose a method of calibrating highly accurate signals of an integrated automatic inspection equipment that minimizes measurement errors of analog voltage and high - precision signals.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.3
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• pp.74-81
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• 2008

The control system of high-precision AC power is important in traffic management lighting and beaconing of aerodromes, etc. To control AC power supply in these load characteristics, inverter systems of AC/DC/AC conversion are widely used in high-precision current control. Therefore, in this paper, a inverter system of constant current regulation using improved measuring technique of feedback current is proposed. Proposed measuring techniques improve response and precision in that it use moving average method of instantaneous RMS for measuring current sensing. Results of the computer simulation and experiment prove the effects of proposed system.

• Journal of the Korean Vacuum Society
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• v.3 no.2
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• pp.190-197
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• 1994

본 연구에서는 DC magnetron 스퍼터링법을 이용하여 고정밀, 고저항 저항체 박막으로 TaNx film을 제조하였을 때 형성될 수 있는 화합물 중 TaN0.1, TaN0.8과 TaN 박막의 Rs와 TCR특성을 평가하 고 film층의 우선방향성을 XRD를 이용하여 판명한 뒤 저항체의 Rs와 TCR에 미치는 영향을 조사하였 다. TaN0.1 박막이 35$\Omega$/$\square$의 면저항값과 안정된 TCR값을 나타내는 것을 알수 있었다. 두께50~200nm 의 TaN0.1과 Alumina 기판 사이에 정(+)의 TCR을 갖는 약 50nm의 Cr층을 증착하였을 때 Rs는 180$\Omega$/ $\square$ 과 TCR는 20ppm/$^{\circ}C$인 적층박막을 제조할 수 있었다. TaN0.1, TaN0.8 과 TaN 시편에서 화합물 형성 에 따른 Ta의 결합에너지를 ESCA를 이용하여 조사하였다. 이상의 연구결과로부터 TaN0.1 film이 TaNfilm 보다 고정밀, 고저항 박막 저항체 제조에 있어 우수한 전기저항 특성을 가지며 Cr 중간층 형성 으로 TCR이 $\pm$ppm/$^{\circ}C$정도로 안정된 고정밀 다층 저항체 박막을 형성할 수 있었다.